Generally speaking, it is normal for people who have no fitness experience to keep their weight unchanged or even gain weight in the first two to four weeks after fitness exercise.

Judging from your coach's arrangement, the problem is not serious, mainly because the muscles of novices are very sensitive to strength exercises. After training, the muscles store nutrients and water, and the muscles grow normally, which leads to the weight rising instead of falling. After the muscle adaptation period, your weight will generally have a steady and obvious downward trend.